Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Clarifying missed app climb gradients

Tech Log The very best in practical technical discussion on the web

Clarifying missed app climb gradients

Old 14th Feb 2024, 13:06
  #1 (permalink)  
Thread Starter
 
Join Date: Mar 2012
Location: EU
Age: 34
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
Clarifying missed app climb gradients

Hello Guys,

As I am getting lost with all that gradient mess please be so kind and help me with uderstanding it
I know that certification gradients for MA are 2,1 for approach climb (with OEI, flaps approach, gear up)) and 3,2 for landing climb. I know also that minimum gradient for MA procedures is 2,5%. Let's assume we are flying to Nice, there is ILS Y RWY04L in use (just as an example) where we have such statement: MACG min 3,0% DA: 301 (for B cat a/c) and MACG 2,5% so then DA is 321. This is the point I am getting lost. If they put 3.0% gradient on the map, AFAIK, that means there is a demand for higher gradient than standard procedural (2,5%). First question - does the gradient from the jeppsen map include OEI? As I know normally procedures are made for AEO, however the name "MACG" makes me think it is missed approach climb hence it takes into account only OEI.
I see that my FMS after computing all the WAT data i put in, gives me approach climb 3,5 and balked landing 4. As 3,5>3,0 I can commence the approach with lower minimas. The question is what about 2,1%. Do I need it somehow? For what exactly I need it or do I even need it at all?
Do i need keep at least 3,0 untill the end of the whole missed approach procedure (end of final segment)?
Is it somehow possible that my a/c will not meet certification requirements for MACG/landing climb under some circumstances (assuming I am operating it within AFM limits)?

Last edited by hellkitty; 14th Feb 2024 at 13:20.
hellkitty is offline  
Old 14th Feb 2024, 17:04
  #2 (permalink)  
 
Join Date: Oct 2007
Location: Location, Location
Posts: 733
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by hellkitty
Hello Guys,

As I am getting lost with all that gradient mess please be so kind and help me with uderstanding it
I know that certification gradients for MA are 2,1 for approach climb (with OEI, flaps approach, gear up)) and 3,2 for landing climb. I know also that minimum gradient for MA procedures is 2,5%. Let's assume we are flying to Nice, there is ILS Y RWY04L in use (just as an example) where we have such statement: MACG min 3,0% DA: 301 (for B cat a/c) and MACG 2,5% so then DA is 321. This is the point I am getting lost. If they put 3.0% gradient on the map, AFAIK, that means there is a demand for higher gradient than standard procedural (2,5%). First question - does the gradient from the jeppsen map include OEI? As I know normally procedures are made for AEO, however the name "MACG" makes me think it is missed approach climb hence it takes into account only OEI.
I see that my FMS after computing all the WAT data i put in, gives me approach climb 3,5 and balked landing 4. As 3,5>3,0 I can commence the approach with lower minimas. The question is what about 2,1%. Do I need it somehow? For what exactly I need it or do I even need it at all?
Do i need keep at least 3,0 untill the end of the whole missed approach procedure (end of final segment)?
Is it somehow possible that my a/c will not meet certification requirements for MACG/landing climb under some circumstances (assuming I am operating it within AFM limits)?
The 2.1 approach climb OEI and 3.2 landing climb AEO are ICAO design minimum gradients. All EASA missed approaches are 2.5 unless terrain or ATC procedures dictate a higher gradient.
Whatever gradient is on the chart, you must be able to achieve it from the missed approach point on one engine, as it is assumed to fail at the MAP (just like your takeoff is assumed OEI). So as long as your perf calculation shows your approach climb gradient exceeding (as yours did) you are fine. You must keep the gradient if OEI until above MSA or reaching platform altitude (so donít accelerate on one engine below MSA or platform as youíre in the unknown). Your company SOP should state this clearly.

If you canít make the gradient on the perf calc, use the higher minima or try packs or bleeds off. If you still canít make the gradient then most companies (and the authorities) allow you to use a takeoff engine failure procedure if one exists for that runway. This is because you will definitely exceed the OEI takeoff minimum gradients when commencing a missed approach from the MAP (youíre higher up and further back). If you baulk the landing (GA below minima) technically you will need to fly the takeoff EFP to assure obstacle clearance if an engine fails as you decide to go around.

Hope that makes sense, Iím typing it quickly over dinner!

Last edited by Mr Good Cat; 14th Feb 2024 at 17:23.
Mr Good Cat is offline  
Old 14th Feb 2024, 17:46
  #3 (permalink)  
Thread Starter
 
Join Date: Mar 2012
Location: EU
Age: 34
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
That makes sense! Thanks. Now it's far more clear.
hellkitty is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.